There are literally thousands upon thousands of creams and serums out there that all promise to turn back the clock and other wishful claims, but at this point there's only one super ingredient that really delivers on such promises. That would be retinoids, friends. (Both over-the-counter retinol and its prescription counterpart Retin-A both fall under this category.) While it was initially used to get rid of acne, blackheads and dead cell buildup in pores, retinol was also found to have incredibly effective anti-aging properties.

It's pretty powerful, so you'll need to tailor its use to best suit your skin type -- luckily it comes in varying forms and strengths. That said, there are a few important things to keep in mind before incorporating a retinol regimen, like what time of day you should be applying it or how long it will take to see results. But once you've found the right balance, you'll be soon on your way to gorgeous, more youthful-looking skin. We worked with a couple top dermatologists to create a FAQ of sorts about retinol, containing five things you need to know about the ingredient, as well as a gallery of our favorite retinol-infused products.

What is retinol, and what are the major anti-aging benefits? "Retinol and Retin-A are both part of a group of derivative compounds of the vitamin A family," says Dr. Howard Murad, dermatologist and founder of Murad skincare line. "Retin-A is the prescription form, and has been shown to reduce fine lines, smooth skin texture and help normalize pigmentation. You can get a prescription from your dermatologist and may see results in short periods of time." On the other hand, he notes that retinol, which is available in over-the-counter skincare formulations, "may take longer to achieve results, but many find it less irritating than the prescription formula."

When should you begin a retinol regimen? "If you choose to use a retinol product, it is generally recommended that you start in your 30s," says Dr. Murad. "By your 40s, it’s time to add a retinol product in your night care routine."

When and how often should it be applied? Retinol is photosensitive and should only be worn at night. Never go outside or into the sunlight with it on; this could cause adverse effects. As far as how often, this varies by skin type and the product. Dr. Murad points out that "it depends on whether you are using prescription Retin-A or over-the-counter retinol. It’s best to begin using retinol products every other night and work up to every night." You could begin to notice changes anywhere from within a week to about eight weeks. However, New York dermatologist Debra Jaliman importantly warns to "use the product sparingly."

What if irritation occurs? "Retinoids exfoliates your skin and may cause it to become sensitive," says Dr. Murad. "It may peel, flake, turn red and become dry during initial use. It is key to use small amounts every other day, until your skin works up tolerance for vitamin-A." Wash with a gentle face scrub a few times a week to clear the top layer of old skin.

Is there anyone that shouldn't use retinol? "There are certain people that shouldn't use retinol," says Dr. Jaliman. "For example, people with rosacea or eczema. It should not be used with a heavy hand and should be used [in tandem] with a moisturizer."